Transmission



Sept 26, 1939. E. oRsHANsKY, JR 2,173,856

l TRANSMISSION Filed June 6, 1935 9 Sheets-Sheet 1 l N lNvENToR ATTORNEYS Sept. 26, 1939.

ayu/imma gum a E. ORSA-IANSKY, .JR 2,173,856

TRANSMISSION 9 Sheets-Sheet 2 Filed June 6, 1935 9 Sheets-Sheet 3 E. oRsHANsKY, JR TRANSMISSION Filed June 6', 1935 INVENTOR Elms Unidas/@Jr BY @zul/ faAA., /da/MJ ATTORNEY-5 'sept 26, 1939.

Sept. 26, 1939. oRsl-lANsKY', JR

TRANSMISSION Filed June 6, 1935 9 Sheets-Sheet 5 ATTORNEYS Sep. 26, 1939. E, oRsHANsKY, JR I 2,173,856

.TRANsmssIoN File@ June e, 1935 9 sheets-sheet -6 Ms Q@ fr. I BYLM M4 M ATTORNEYS Sept 26, 1939. E. oRsHANsKY, JR I 2,173,856

` TRANSMISSION Filed June e, 1955 9 sheds-sheet 7 INVENTOR ATTORNEYS Sept. 2e, 1939.

E. oRsHANsKY. .JR

TRANSMISS ION Filed June 6, 19555 9 Sheets-Sheet 8 ATTORNEYS Sept 262 w39, E. ORSHANSKY, JR @,W@

TRNSMSSIDN Filed June s, 1955 l 9 sheets-sheet ATTORNEYS Patented Sept. 26, i939 f A Vai'zass 'rneNsivnssioN Elias rshansky,'.lr., Newr York, N. Y., assigner to The Aci-otorgue Gompany, New Haven, Conn., a corporation of Connecticut Application .inne 6', 1935,Serial No. 25,201

15 'Claims This invention relates to a structurally and functionally improved transmission capable of use in numerous diiierent associations, but primarily intended .to be employed in transmitting a power drive from a driving member, such as an internal combustion motor, to a driven mem-l ber such as the axle or axles of a vehicle.

It is an object of the invention to furnish a transmission capable of use in connection With hoisting machinery, rail vehicles, road vehicles, and in numerous other associations and by means of which the conventional gear shift heretofore employed may be dispensed with.

A further object of the invention is that of providing a transmission capable of being associated with a prime mover of relatively high power and which transmission in such association will provide for a variable range of speed on the part of the driven member.

In other words, great dimculty has been heretofore experienced in providing what is commonly known as a gear shift for use in association with motors developing in excess of a lcertain power.

The present invention provides a transmission which may be employed in connection with such motors.

thereof.

A still further object of the invention resides in providing a transmission which will be automatic in operation, and which, under all circumstances, will be capable of developing a variable torque.

Another object is that of providing a mechanical transmission which, as afore brought out, may

or operator of the vehicle.

Still another object is that of providing a transmission embodying relatively few parts, each individually simple and rugged in construction, and which parts may be assembled at comparatively small cost to furnish a unitary apparatus operating over long periods of time with freedom from all diiculties.

(Cl. 'Z4- 189.515)

of the internal combustion type and showing in association therewith transmissions constructedn in accordance with the present invention;

Fig.4 2 is a longitudinal. sectional View taken along the lines 2-2 and in the direction of the arrows as indicated in Figi;w

Fig. 3 is an enlarged endgelevation with tain. parts broken away todiscloseunderlying? mechanisms;

Fig. 4 is a sectional side View of a transmission unit and taken along the lines -G and in the .direction of the arrows as indicated in Fig. 3;

Fig. 5 is a partly sectional side View taken along" thelines 5-5 and 'in the direction of the arrows as indicated in Fig. 3;

Figs. 6 andA 7 are transverse vsectional views tak'en along the lines 6 6 and 'l-"i, respectively', and in the direction of the arrows as indicated Fig. 8 is a graph showing the manner in which the effective power of the transmission `is divided under different conditions of operation thereof; f

Fig. 9 is a fragmentary section taken along lines 9-9 of Fig. 7;

\ Fig. 10 is an enlarged fragmentary section showing a detail of the cylinder block;

Fig. l1 is a section taken along lines H ii as indicated in Fig. 10;

Figs. 12 to 15,` inclusive, show diagrammatically the position of the various controls during the several operating stages of the apparatus;

Fig.-.16 shows an alternative'form of difierential mechanism; and

Fig. 17 is a transverse sectional. view 'taken along the lines I'l-Il and in the direction of the arrows as indicated in Fig. 16. v Y

As afore brought out, the present invention is ideally suited for use in connection with so-called Diesel and similar types of locomotives. In fact, one feature of the present invention is that of teaching the proper application of a transmission to a vehicle of this type. However, as afore brought out, according to another aspect of the invention the transmission may be employed in numerous different associations without departing from the teachings of the present invention. Accordingly, the present drawings and specification are to be taken in an illustrative rather than Thus, referring primarily to Figs. l and 2, it

will be observed that flanged wheels are indicated at I0 and which are rotatably associated with a conventionally mounted truck generally indicated at II.

Supported within the body of the vehicle is a prime mover I4 such as a turbine or internal combustion motor, and extending from this motor is a driving shaft I5 to which is coupled a bevel gear I6. A shaft I1 may be disposed at right angles to the shaft I5 and have a tube I8 concentrically disposed with reference to a. portion of its body. Bevel gears I9 and 20 are secured to the shaft I1 and sleeve I8, respectively, and mesh with the teeth of gear I6. A housing 2| encloses this assembly of the parts and mounts the same by means of anti-friction bearings 22, this housing extending to the floor of the vehicle body I3 and through the same to a position preferably midway between the axles I2. Secured to the lower end of the sleeve I8 is a bevel gar 23 and a similar gear 24 is secured to the shaft I1. These gears mesh With the teethv of gears 25 secured one to the inner ends of each of the shafts 26, which latter form part of two different transmissions cooperating with the respective axles of the truck. As shown, the last described parts are all enclosed in a housing 21, which may form a continuation of housing 2I,

and which, in common with the former housing;

may mount anti-friction bearings 28 for the rotatable support of the several shafts and elements disposed within it.

A s a consequence of the structure described, itl

pressures, itis preferred to associate a transmis sion with each axle; it being obvious that if this lis not done, larger transmissions operating (as hereinafter explained) at relatively high pres'- sure would be necessary. Additionally, as a conl sequence of employing two drive members, i. e.,

the shaft I1 and sleeve I8, the torque is neutralized and, moreover, it is feasible to employ at the lower end of these driving members a double gear drive for both of the shafts 28. In other words, each of the bevel gears 25 or its equivalent isengaged by both gears 23 and 24. If this were not the case, the entire strain of driving would fall upon the zone of contact between, for

example, gear 24 and gear 25. Under these circumstances it would be preferable to employ larger gears at this point, and this again is objectionable, if for no other reason than' due to the fact that the available space is relatively conjstricted.

In Fig. 2 there has been indicated controls 29 and 30 which are located at a space accessible t'o the engineer. Both of these controls may take the form of readily operable levers or handles connected to valves (not shown) Awhich govern `the ow of uid through tubes 3 I 32, 33 and 34. The control 29, when operated, throws the mechanism of the transmissions to a condition at which, when power is applied, the axles l2 will be driven clockwise or counter-clockwise; in other words, ahead or reverse. Control 39, when thrown to its extreme positions, causes the mechanism to assume a neutral or driving con.- dition. Consequently, the control 29 may be actuated to cause the drive to be effected in the deof any'suitable type, the position of suchuni versal having been indicated in- Fig. 2. The driven element of each of these'universals forms a part of or is coupled to shaft 36 of each transmission, and which shaft extends into the transmission casing 31 and has at its inner end a further universal 38 couppling it with a shaft 39, which latter is supported upon anti-friction bearings 46 associated with the casing 31. `It is found that some degree of vertical movement occurs under conventional forms of construction between the -body of the vehicle and the truck, and itis with this inv mind that the universals 35 and 38 are provided. Following the design herewith suggested, this movement does not materially exceed substantially five degrees, and it`wi1l therevfore be understood that no real power loss will occur. As shown in Fig. 3, the'shaft- 39 rotates a bevel gear 4I, the teeth of which mesh with a gear 42 mounted upon a shaft 43. 'I'he latter has secured to ita gear 44, the teeth of which, in

turn, engage the teeth of a gear 45 mounted upon a counter-shaft 46. This gear in turn meshes with the teeth of a gear 41 which is splined or keyed to a hub 48 encircling a shaft 49 and spaced therefrom. The hub 43 may rotate freely by being mounted, for example, by tanti-friction bearings 59 interposed between it and fixed portions of the housing 31. The hub 48 is continued in the form of a diskv 5I mounting one end of sllafts 52,4 the opposite ends of which are mounted by a hub-disk 53 integral or otherwise xed with respect to the disk 5I. The disks are also supported by bearings 50, and planetary gears 54 are associated one with each of the shafts 52. These gears encircle a sun gear 55 which may be integral with or otherwise flxedly secured with respect to the shaft 49. The gears 54 are in turn encircled by a ring gear 56, which latter is supported in position as, for example, by

securing to the opposite side faces thereof guides or encasing members 51, which guides ride upon anti-friction bearings 58 also inv association with fixed portions of the casing 31.

The ring gear 58 has secured to its periphery or is formed with a series of teeth 59 which mesh with the teeth ofv a gear 6I! secured by splining or keying to a shaft 9| 'I'he latter is rotatably supported by anti-friction bearings 52, and it is thus obvious that, if the shaft 49 is held against rotation and the gear 45 is rotated, the gear 41 will rotate, and in such rotation turn 'the hub members 48 and 53, carrying with them the gears 54 around the gear or gear portion 55. This will result in the gear 58 being rotated at an accelerat'ed rate and in the same direction, thus caus- 75 v 2,178,866 'ing a driving of the gear 60 and rotation of the conditions act as pumps. It will be observed that each of these units includes a wobble plate 63 pivotally secured as at 64 tol its respective shaft.

Encircling each of these shafts and extending` between the same and the inner edge of the wobble plates are collar members 65. Connection between these members and the plates 63 is provided by links 66 which have their ends pivotallyconnected to these elements. In each of these structures the collar member 65 may be reciprocated along the shafts mounting the same to increase, decrease, neutralize, or (in the case `of the upper unit) reverse the angularl'ty of the plates with respect to the shafts. Such reciprocationv may, for example, be achieved by boring each of the shafts 49 and 6I and extending into such bores rods |66. Pins ,6l are associated with each of these rods andride through slots 58 formed in the shafts, these pins being connected at their ends to the collar members 65. The outer ends of the rods |66 are in each instance coupled to cup members 69 in the nature of pistons and which cup members have their outward movements limited by stops 1li. The connections which exist between the rods and these piston like elements is preferably in the nature of a thrust bearing 1|, so that as the rods |66 rotate with respect to the members 69, the latter may be projected andv retracted to achieve the results aforenoted, such movements being eifected by any suitable mechanical connection as, for example, rock shafts 12 and H9,

to which crank arms 13 are secured and the that the cylinder assemblies of each unit actu-A ally include two spaced blocks, the cylinders or` bores of which are aligned, so that inter-connecting pistons 16 may alternately ride into the opposed cylinders of the different blocks. The pistons are formed integral with or are firmly secured toconnecting brackets 11, having arms, the inner faces of which rockingly mount slipper elements 18. These elements slidably contact the opposite side faces of the plate 63, and it will thus be understoodthat if the unit associated with the shaft 6l is viewed as a pump, a turning of this shaft'relative to the cylinder blocks 15 encircling the same (with the wobble plate in the position shown) causes reciprocation of the pistons within the cylinders which accommodate the same. It will, ofcourse.be understood that any one of a number of obvious constructions could be employed to allow of any proper degree of extreme angularity on the parts of plates B3 and to also assure of constant contact between the blocks or slipper elements 18 and the faces of the plates. To assure a proper guiding of the parts, the bracket element 11 may be formed with a suitable number of bores through which rods 19 pass, these rods having their opposite ends connected-to the opposed cylinder blocks. Also,

as shown especially in Fig. '7, the slipper elements 18 may have extensions or other suitable guid-` .bran'ches as4 indicated` at 9B. these branches a port 9| is provided. Within the ing provisions for preventing their displz'icement. Obviously, as the rods |66 are adjusted to cause decreasing angularity on the part of the plates 63, the amount of reciprocaton occurring on the part of the pistons is decreased to a corresponding extent. With the plateextending at right .angles to the shaft mounting the same, no reciprocationwill occur, and if one continues to shift the plate in the same direction, reverse reciprocation of the pistons will occur. In other words, when before the piston traversing a given zone was projected, it 'would now be in course of retraction while traversing such zone.

Each of the cylinder blocks is formed with gear teeth 80 or else has secured to its body a `member providing such teeth. As aforestated,

each of these blocks is rotatably supported, and this support may take the form of bushings 8l interposed between the inner face of each block and an extension forming a part of the casing section 31. In their outer faces each of these blocks may be grooved to receive the inwardly lextending edge portion of a ring 8i mounted upon the casing by bolts B2 and carrying packing 33 of any suitable character, which rides against the outer face of each block. In this manner, the blocks are mounted for rotational movement. This structure, however, provides anv additional factor, in that passages 85 are formed at a number of points between the outlet or pressure passages of the assemblies and the spaces which exist between the outer ends of the cylinder blocks and the packing 83. In this manner, and in view of the fact that the rings 8l are stationary, the cylinder blocks will be constantly forced outwardly and into sealing contact with the surfaces of the casing sections which abut their ends.

These sections have been best indicated in Fig. 6, taken in conjunction with Fig. 4. It will be observed that the one particular casing section shown at this point has compartments 81 and 8S. The first of these is defined by'a partition or wall 89 which has its body in the form of two sections, each including a radial series of Within each of compartment 88 ports 92 are formed at points between the branches 90. The ports 9| and92 provide two annular series of openings arranged to register with the outer ends of the cylinders or bores formed -in the blocks 15 as the latter are shifted to permit of such registry. 'I'he ports 9i and 92 should be spaced so that the end of the cylinder may be entirely out of register with any port and sealed by contact with the surface of the casing section which it abuts.

The construction of a unit for motor and pump purposes and embodying an assembly of apparatus similar to the foregoing has heretofore been attempted. One diiiiculty in connection with a. construction of this nature which has existed, however, is that with a ported member and cylinder blocks which are rotatable, it is essential that the contact or sealing` provision between these elements be suiliciently intimate that no substantial escape of fluid can occur. 'I'his of necessity calls for considerable frictional engagement of these parts or auxiliary elements associated with them. vSuch intimate contact in turn prevents excessive relative. rotation, in 'that the friction will be so great that a destructive action will be set up quite aside from the fact .that .a large mechanical loss will exist incident to the parts engaging and moving with 'respect to each other.

This diiiiculty is overcome according to the present invention, in that, as afore brought out, the cylinder blocks are rotated, but this rotation does not involve a high speed of the parts relative to each other, although intimate and proper sealing contact does Considering one speciiic proposal for overcom-` six pressure actions and six suction actions. This,

of course, is conceding that the wobble plate is presenting in effect a single dwell and a single cam surface.'. It will be understood by those skilled in the art that if this plate is actually a cam presenting a number of duplicate surfaces,

- the action-afore noted will be multiplied accordapparatus in which more than one pair of ports in excess of cylinders would be present, or in which there would be more than vone cylinder in excess of the-number of ports. However, in the interest of simplicity, and according to the preferred design, thecylinders of any given block should number one less or one in excess of the pairs of ports employed.

This results in a Vernier a'ction between the cylinder block and the ported member by which the cylinders, during a fraction of a revolution of the cylinder block-and a concurrent complete revolution of the driving shaft--are successively connected with an inlet and an outlet port corresponding in each case to the stroke of the piston. Consequently, this construction permits the carrying of sufficient pressure between the cylinder block and the ported member, while due to the low speed of rotation of the block the requirements of a thrust bearing are not exceeded, although the' high contact' pressure existing between the parts limits leakage. Of course, for any given pressure the power required to rotate the cylinder block is a fraction of the power required to rotate it with previous methods of construction, and the relation of the two power requirements are as their respective speeds of rotation. summarized, the losses due to rotation of the cylinder block are much lower, incident to the low speed of movement of this block, and the leakage is much less, due' to the possibility of carrying high pressures between the cylinder block and the ported member.

While it is, of course, feasible to assure sealing contact between the cylinder block and ported member in a number of different manners,V it is preferred, as heretofore brought out, to employ ports 85 communicating with a space existing between the member 8i and the outer anged portionI associated with the outer ends of the ber.

cylinder block. In this manner, uid under high pressure is forced into this space, and acting against the packing 83 in effect forces the cylinder into intimate' contact with the ported mem- Before concluding consideration -of this point, attention is directed to Fig. 10, from which it .will be obvious that, if desired, the outer iange of each cylinder block might be formed by a separate plate 93, which may be applied in position after the member 8| and the packing 83 carried thereby are properly disposed with reference to the side wall of the block. Also, as shown in Fig. l1, the ports 94', formed in the plate 93, may have a configuration corresponding to the outline of the ports 9| and 92.

As afore brought out, the cylinder blocks are rotated, such rotation being preferably effected by employing gears or gear portions 80. As illustrated in Fig. 9, these gear portions are engaged by gears 95 secured to a shaft 98 suitably mounted for rotation by the several casing sections 31. Shafts of this nature are provided one for each of the two units and rotation of one of these shafts is assured by having associated with the same a gear 91 meshing with a gear 98. xed to the shaft 6i, while the shaft for the second unit is similarly rotated by a gear or gear portion 91 meshing with a gear 99 moving with the shaft 49; The relationship of the several gears 98 vor 99 and 91, 95, and 80 is such' that the ratios afore indicated occur, i. e., to each'rotation of the driving or driven shaft a one-seventh rotation of the cylinder block occurs. Of course, if one or more cylinders than pairs of ports is employed, the rotation of the cylinder block will be in a direction similar to the shaft, while if one less cylinder than pairs `of ports is employed, such rotation will be counter to the dire'ction of rotation of the shaft. A

With the foregoing construction present, and if the shaftr49 is maintained stationary, we have heretofore traversed the fact that the gear will cause an accelerated motion on the part of ring gear 56, which motion will be transmitted through gear 68 to the shaft 6I. If the wobble plate 63 of the lower unit (as viewed in Fig. 4) is in a position at right angles to the axis of the shaft 9|, it is apparent that under these circumstances no driving of the parts, and especially the shaft 49, will occur. In other words, while the cylinder block of this unit will rotate, carrying with it the pistons, no reciprocation of the latter willk occur. If now the shaft 12 is adjusted to cause the rod |66 to shift and to correspondingly incline the plate 63 of this unit with respect to itsformer position, the pistons will be reclprocated to expel oil or other suitable fluid with which the apparatus 'is filled through the ports 9| and to draw iuid through ports 92. Still considering Fig. 4 and with the plate o'f the upperunit in the position shown, this flow of fluid will cause the upper unit to be driven as a motor. In other words, the pistons of this imit willbe reciprocated, and incident to the slip elements 18 the plate of the upper unit will be rotated at relatively high speeds, thus correspondingly rotating vthe shaft 49. Splined or otherwise suitably secured to this shaft is a gear i90, the teeth of which mesh with a gear llll secured to the driving axle l2. Now as the shaft 99 begins to rotate, the gear 45 will not solely drive the gear 56, but the gear or gear portions will also be driven by the planetary gears 54.

.fis the inertia to movement is overcome, the speed of rotation of the shaft 48 will increase so that a constantly greater amount of the drive will be transmitted directly by the gearing 45, 54 and 55 part of dshaft 8i will cause constant acceleration on the part of shaft 49. When shaft 6i completely ceases to rotate, it -is apparent that a direct drive will follow from gear 41 through the planets 54'to gear or gear portion 55, thus rotating shaft 49 at high speeds. In fact, and

for the reason that gear 56 is stationary, this condition mightalmost be likened to an over` drive. In other-words, the teeth of the planets will engage the xed teeth of the gear 56 and drive at accelerated speed the gear 55. While the ratio might be varied in numerous respects, the parts as illustrated would cause the shaft 49 to be driven at approximately 1200 R. P. M. with the'gear 4l being driven at approximately 400 R. P. M., this, of course, being predicated upon the' assumption that gea'r 56 remains stationary. The shaft 6I will gradually ceasev rotation because the unit which has heretofore been the motor (i. e., the upper unit' as viewed in Fig. 4) will be controlled to' cause the plate of the same to assume a position increasingly at true right angles to the axis of the shaft 49. As

this condition is approximated, the pistons in the upper unit can no longer reciprocate, and viewed from one aspect one might state that under these circumstances the entire upperunit acts as a valve mechanism which prevents a flow of fluid from the lower unit, which has heretofore been acting as a pump. The governing means which achieves this result will be hereinafter described in detail, but short of reaching the conditionai'ore noted, it `will he apparent that as the speed of the upper unit (acting as a motor) increases, the speed of rotation of shaft d@ increases and the amount of the drive directly from the gear l? through the gears 54 and 55 also increases. This is caused by a drop of pressure in the entire system incident to a shifting of the plate @i of the lower unit responsive to'an action .ment Under these circumstances, gear 56 will not turn, and substantial stoppage of shaft Si follows. It will, of course. be understood that complete stoppage of the shaft 6I will probably never occur, or else will occur for only a very small fraction of the time during which the unit is operating. However, with the shaft Si substantially stationary, it will be understood that the so-called "direct drive occur. Also (as afore noted) this drive will actually result in the shaft 49 rotating substantially three times as fast as the. gear 41 .is ro.- tated. If, now, the upper unit has its plate shifted to a point at which such unit beginsto functioning in the latter manner, it will obviously rotate in a direction counter to the direction in.

which it has heretofore been rotating. This will cause thevshaft Il to be driven in a similar motor.

afore noted will direction and the-gear will now become a driving gear serving to rotate the gear 551m a direction contrary to that in which it has heretofore been rotating. Such driving will be transmitted by the planets 54 and consequently the shaft 49 will have its rotation accelerated. Under these circumstances, and operating under maximum conditions, the shaft 49 will be rotated approximately six times to each revolution of the gear 41.- In other words, we have heretofore seen that a substantially three to one drive occurs with the shaft 5I stationary or substantally stationary, with the upper unit operating as a pump and the lower one operating asa This effect will bev multiplied by two,- giving the results afore noted.' Of course, the

'ratio of the variousparts might be altered in nient of a given installation.

Returning to consideration of Fig. 6, it will be apparent that there is no diillcultyA involved Vin the interconnection of the upper and lower units of the transmission in that they are permanently connected through the compartments or areas lil! 30 with the same. Fluid expelled from the cylinders of the upper unit iows through the ports @2 of such unit, and thus reaches the compartment tt. Of course, when the plate of the upper unit is in a position such that this unit acts substantially as a valve, then substantially no fluid will dow from either compartment. Conversely, when the upper unit acts as a pump, fluid under pressure will be expelled from the-ports si of such unit andbe received through the correspondingly identified through such ports into the cylinders in registry ports of the lower unit to drive the latter as an motor. An oil sump W2 is provided adjacent compartment 88 and communicating with the same through openings w3, it being, of course, obvious that .any other and suitable substitute might be employed in lieu of the sump.l

Communicating with compartment 3l by means of passages |04 are cylinders l"l5- m6, which may be formed in the -casing of the transmission or in a block arranged in juxtaposed relation thereto. 4

One cylinder forms a part of the governing means vfor one' unit and air cylinders iin-Hi8 are arranged adjacent the cylinders lili-m6 and are '3S-34. In each of the air cylinders a piston m9 is mounted, vthis piston being mounted by or coupled to a rod lin and serving in its reciprocation to oscillate--in the case of cylinder IUT-shaft l l I and in the case of cyunderloa-shartm.- 'rnc valves associated with controls 29 and 30 are pre'- erably of a type which will: (a) connect the tubes '3l and 33 with a source of compressed air flowing through pipes H3; (b) will connect tubes 32 and I4 to such source of compressed air; (c) will/allow the compressed air to escape from these tubes.

|I4 are connected to or mounted by rods IIS extending beyond the ends of the cylinders, and these rods are connected to shafts ||1 and |I8 so that as the rods are projected and retracted these shafts will oscillate.

Now, referring to Figs. 12 to 15, it will be observed that there has been diagrammatically illustrated the parts just described, as well as the linkage coupling the same to the shaft 12 govern- ,ing the position of the plate of the lower unit, and

shaft I|9 governing the position ofthe plate of the upper unit. In these views, and for the sake of avoiding confusion, piston rods have not been shown; nor have the connections which exist between the shafts 12 and I I9 and the wobble plates been illustrated. Considering especially Fig. 12, it is to be understood that the full line position of the parts shown indicates the positions these parts assume under the initial stages of forward drive. 'I'he positions indicated in dotted lines in this view is the condition of the parts under the so-called neutral condition of the transmission. Connected to shafts I I 2 and I I by means of arms |20 and I 2| are rods |22 and |23. The rst of these rods has its outer end pivotally connected to a lever |24 which has its lowerend pivotally supported as at |25. 'I'his lever is link-connected as at 2s to a second lever |21 which has pivotauy connected to it the outer end of rod |23, such connection occurring at a point short of the end of lever I 21. link |28 to a lever |29 `and at a point midway between the ends of the latter. Secured to one end of lever '|29 `is a link |30 which connects through to crank |3| to shaft I I9. Secured to the opposite end of lever |29 is a link |32 connected by a crank |33 to shaft I I8. A lever |34 has its body rockingly connected by a link |35 to the lever |24. One end of lever |34 is connected by a rod |36 to a crank |31 secured toshaft 12, while the oppposite 'end of this lever is connected by a rod |38 to a crank |39 coupled to shaft II1.

With the parts inthe position shown in dottedV lines in Fig. 12, it will be apparent that controls 29 and 30 have been shifted in such manner that the piston within cylinder |08 is in "neutral" position, while the piston Within cylinder |01 is maintaining the parts in ahead position. The plate of the'upper unit will, under these circumstances, have assumed the position indicated in dotted lines incident to the fact that the spring II5 within the cylinder |05 will have rocked the shaft I|8 in a clockwise direction, with the result that shaft IIS will have been rocked in a counter-clockwise direction, thereby resulting in this positioning of the parts. 'I'his follows because substantially no pressure will exist within cylinders |05 or |06 for the reason that the plate o'fthe lower unit will be in a position substantially at right angles to the axis of the shaft 6|. Consequently, with the gear v41 driving, the only action which occurs is a spinning of the plate of the lower unit with no reciprocation on vthe part of the. pistons.

However, as air pressure is admitted into cylinder |08, due to a shifting of control 30, the piston within'this cylinder is caused to assume the position shown in full lines in Fig.

This end of the lever is connected by aA 12. This will result in the plate of the lower unit being caused to assume a slightly inclined position, so that the pistons ofsuch unit will begin to reciprocate and pressure will now be built up within compartment 31 and be transmitted through ports 9| to the cylinders of the upper unit. Also, due to the shifting of the piston within cylinder |08, the linkage will have been shifted to cause the shaft ||9 to rock so as to shift the plate of the upper unit from the position indicated in dotted lines to the position shown in full as shaft 49 begins to ypick up speed, the pressure will diminish, and this diminution of pressure allows the pistons within Acylinders |05-I06 to shift in response to the urging of the springs I I5,

so that a condition such as is illustrated in Fig.

13 occurs. As seen in this iigure, the plate of the upper unit is in a position substantially at right angles to the'axis of its shaft 49. The position of the plate of the lower unit is such that it extends at a considerable angle with respect to the perpendicular. Under these circumstanceswe have'alreadytraversed the fact that the upper unit will, in effect, act as a valve, thereby substantially locking the lower unit, and especially the shaft 6|, against rotation. 'I'his is the condition of so-called direct drive, in which, actually, with the parts proportioned as shown, a substantially one to three drive occurs on the part of gear 41 with respect to gear |00. If, of course, with the parts reaching this condition, a

suddenly increased load should be thrown on the transmission, as would be the case if the vehicle had reached an abrupt grade, then the parts might remain in the position shown in Fig. 13, or might, in fact, drop back to the position shown in full lines in Fig. 12. -It should be borne in mind that according tol the preferred embodiment of this invention, the engineer will only shift the controls to, for example, "ahead and go, and the parts automatically assume proper conditions with respect to each other, incident to the pressure which exists in compartment 41, and which pressure is,in turn, transmitted to cylinders |05 and |03, to produce the results desired. With no un'usuiail-l condition present, however, the piston cf cylinder |03 will shift from the position shown infFlg. 13 to the position shown in Fig. 14. It will be borne in mind that the spring I|5, cooperating with this piston, is

relatively weak when viewed in commotion with I the spring associated with cylinder |05.` Therefore, so long as material pressure exists, the spring of cylinder |06 willbe incapable of Shifting the piston toits fully retracted position. With a tendency of the ,torque of shaft 49 to drop, it will be found that the pressurewithin cylinder |06 will drop to an extent such that it may shiftto the position shown in Fig. 14. This will not affect the position of the plate of the lower unit, but will cause the plate of the upper unit to assume what might be termed a "reverse position. Consequently, the upper unit will now begin to function as a pump, and the lower unit will be driven ai a motor, .thus driving the sha 6|, with the results aforenoted.

The parts will remain in the position shown -in Fig. 14, even if 'a down grade is encountered and even if the axles I2 are driving the trans 75 mission rather 'than the prime mover driving the axles. Under such circumstances, the shaft 49 would present a minus torque, and consequently the piston of cylinder |06 would be free to shift to its extreme of travel. This would cause the effective displacement of the cylinders of the upper block to equal the effective capacity of the cylinders of the lower block, despite the fact that the plate of the lower block will be in the extreme position vof angularity. Consequently, an effect will be presented which one might term as being in the nature of free wheeling,- but it will again be understood that the instant the shaft 49 presents resistance to driving, the parts will return to the position shown in Fig. 14, and if the resistance continues, or increases, these parts might, in fact, drop back to the position shown in Fig. 13, or in full lines in Fig. 12.

With the. vehicle-or any other unit to which the transmission ist applied-reaching a stationary condition, the engineer is free to throw the parts into reverse. Thislhas been illustrated in Fig. 15. It willJ of course, be understood that control 3U is primarily brought to a neutral condition. Control 29 is thereupon brought to a condition such that a reverse drive is to be effected. Thereupon. if control 30 is actuated, so that the latter assumes the gov position, theV pistons Within cylinders |01 and |08 are shifted to the right as viewed in Figs. 5 and 15. Incident to the linkage the plates of the two units are also'l shifted so that the plate of the lower unit again assumes the position shown in full lines in Fig. 12. However, the plate of the upper unit is shifted to the position which it has assumed under the condition of the parts described under Fig. 14; or, in fact, this plate may even shift upto the extreme positionA which it would have assumed under free wheeling conditions. This -positioning ofthe parts, and despite the existence of pressure in cylinder we, will occur, due to the deliberate shifting of the mechanism incident to the air pressure existing in cylinder mi', which will cause such shifting of the piston. Under these circumstances, it will, of course, be understood that rotation of the gear M' will cause -rotation of the hubs 5|53. However, due to the fact that the inclination of the upper plate has been reversed, the shaft 49 will offer far greater resistance to turning than was-the case when the parts `were in the position shown in full lines in Fig. 12. Consequently, the shaft 5l is turned, and the lower unit acts as a pump to drive the upper unit as a motor ina direction reverse from. that which,` under preceding conditions, it has been rotating. This naturally results in a reverse driving of the shaft 49, and any tendency of the planets E4 to drive the shaft 49 in an opposite direction will be overcome by the power exerted by the upper unit.

As -has been described, the operation of the transmission consists of changing the speed relation of the output shaft with respect to the input shaft by a variation of the speed (both in magnitude and direction) of the third member .of the differential gearing, which third member is not fixed to either the output or the input shaft., 'Ihis third member, however, drives (or is drivof the output shaft with respect to the input shaft Y i Ywill. produce a'variable capacity in the hydraulic Vmit of whicnshartsl is a part.

` Since due to the nature of the .differential gearing allforces acting on all components of the dif-1 ferential are in a constant relation, shaft 6l will be turned by a constant torque irrespective of its speed, this torque being applied even when shaft 6| is stationary, as in Fig. 13. (It is assumed that the torquev of the prime mover is constant, but if it varies, all the other forces in the differential vary likewise, in consequence of which fact the torque on shaft 6| is constant with respect to all the forces of the gearing.)l

It will be seen from Figs. 12-15, andFigs. 3, 5 and 6 which show the controls, that it is possible to change the pressure of oil delivered by leither inclination of the plates 63 (Fig. 9).

Considering, for example, the parts as illustrated in full lines in Fig. 12, it will be understood that the pressure delivered by the lower unit is very high, due to the snfall inclination of its plate. Consequently, the force on the upper motor unit is very much higher thanl that driving the lower unit, due to the fact that the inclination of the plate of motor unit is very much greater than that of the-pump unit, the pressure being equal in both units.

It must be understood that the oil pressure exists in the system solely due to resistance to turning on the part of shaft 49, and varies` directly as such resistance. Consequently, as the resistance to turning decreases, the nil=pressure will likewise decrease, causing the controls (Fig.

`mission will be in a true condition of overdrive.

With :reference to Fig. 8, it is seen that one of the advantages of this system. of power transmission is the fact that during the running of the locomotive only a part of the power is transmitted by the hydraulic system. Thus, it will be seen that if the resistance to driving is such that the parts assume the position illustrated in Fig. i3, the upper unit will act Vas a valve, refusing oil from. the lower unit, and in eect the hydraulic system will transmit no power. This condition is shown at point a in Fig. 8. The ratio at that point is identified arbitrarily Rzl, and corresponds to a road speed of roughly 90 M. P. H. on one type of locomotive.

If, now, the resistance rises, the controls will be actuated, due to the rising oil pressure, as above described, and will cause a change of ratio in the direction of Rz (Fig. 8), which corresponds to the position of the parts as shown in Fig. l2. Under these circumstances, more and more power will be transmitted hydraulically, in the relation of:

Power transmitted hydraulica11y= 100%(Bg-1) Power transmitted mechanically l =ioo%ioo% g1) (This condition does not hold true for ratios of higher than R; 1, the relation in that range vbeing as shown by. the part u-d of curve of Fig. 8).

This relation is shown by the curveV of Fig. 8, which dividesgthe total power into zone b, or power transmitted mechanically; and, zones c, or power transmitted hydraulically.

By virtue -of the' design,` the actual reduction ratio isy approximately Rzl, but the -relations hydraulic unit at a given torque, 'by changing the for any ratio.

In the case of the overdrive, the highest possible ratio is one in which all the power is transmitted hydraulically, and it corresponds to approximately R:1/2, due to the properties of the differential gears. Ihat is, shaft 49 will turn approximately twice as fast as it does under conditions of point a and ratio Rzl.

summarizing, at the start almost all the powe is transmitted hydraulically at high pressure. As pressure drops, less and less power is transmitted hydraulically, and vmore and more mechanically, in the relations of the curve of Fig. 8, the amounts of power transmitted hydraulically and mechanically being dependent solely on the ratio with respect to point a.

At the point corresponding to Fig. 13, no power fis transmitted hydraulically. Beyond that, in the direction of still lower ratios (Fig. 14), the amount of power transmitted again increases as shown in Fig. 8.

Briefly reviewing the teachings of the present invention, it will be understood that a transmission is provided which, as afore brought out, may be used in connection with hoisting machinery as well as road and rail vehicles. It may also be employed in such associations and may be coupled to a turbine or similar prime mover, although it will probably find its primary utility when coupled to an internal combustion motor of either the Diesel or gasoline types. When so employed it functions perfectly in lieu of a generator-motor installation, and efficiently transmits power. The employment of a mechanical transmission of a conventional nature is, of course, not feasible, because the power developed by the prime mover is such that a more or less conventional transmissionl employing a clutch could not withstand the strains of such association for any reasonable period-of time. The use of a transmission of the nature proposed in the present application and in lieu of a generatormotor transmission is dictated by virtue of the saving of expense, aside from the fact that it isY y additionally possible to economize .on gross weight, and also in the continued maintenance thereof. Moreover, a relatively unskilled person can operate the present transmission, whereas the services of highly skilled engineers are necessary to an installation embodying, for example, a Diesel motor coupledto a generator and in turn coupled to` a driving motor which is finally coupled to driving axles or their equivalents. Proper torque is developed by the present transmission under all conditions of load, and the parts automatically shift and acuust themselves in accordance with this load and with a view to preserving a proper balance or ratio of drive between what might be termed the mechanical side of the transmission and the hydraulic side thereof.

Viewing the illustrated embodiment of the invention, and briefly traversing the operation. of the several parts, it will be appreciated from a review of the foregoing that with the prime mover I4 operating, the shaft I1 and sleeve I0 simply causes, through planets 54, a rotation of gear 56, thus driving gear l00 and shaft 6I. This, however, does not result in a reciprocation of pistons 16, due to the fact that the plate 03 of the lower unit'extends in a plane perpendicularV shown in Fig. 8 and described above hold true to the axis of the shaft 6|, and consequently no pressure is built up in chamber 81, so that there will be no driving force transmitted to the pistons 'of the upper unit. Asa result, there will be no real tendency on the part of shaft 49 to turn, and consequently gear |00 will remain stationary. 'I'he operation of controls 29-30 to cause a shifting of the parts to the positions shown in Fig. 12, results in the rotor or plate of the lower unit being shifted angularly and in the yplate of4 shaft 49 increases, the pressure in chamber 81 will drop, and the parts will assume the position shown in Fig. 13. In such positions, the upper unit refuses to receive fluid pumped by the lower unit and consequently the latter reaches a point where it is substantially locked or stationary and shaft 6| will not turn. The gear 60 will, under these circumstances, be stationary and restrain the gear 66 from moving. With a continuation of drive from gear 41 this will cause planets 54 to drive the shaft 49 at a relatively high speed. As this speed increases (and the pressure within compartment 81 continues to drop) the parts finally shift to the positions shown in Fig. 14, in which the shaftl is again rotated,.but in a direction counter to its previous direction of rotation, which occurs due to the fact that the upper unit is now acting as a pump and the lower unit is acting as a motor.

In this connection, -it will be appreciated that the plate 'of the upper unit is so mounted, and that its governing mechanism is of such a nature,

,that this plate may swing from the extreme position indicated in dotted lines in Fig. l2 (or even beyond such position) to the position indicated in full lines in this gure. The plate of the lower unit, however, is preferably so arranged that while it may swing in a clockwise direction and away from a position perpendicular to the axis of upper and lower units to assume the positions shown in Fig. 15, the lower unit will again function as a pump, and the upper unit as a motor, but" the direction of rotation of the latter unit will be counter to the4 direction in which it has heretofore removed.

Before concluding consideration of the mech anism aforedescribed, itis desired to emphasize that while it maybe conceivable to design units in which various numbers of ports and cylinders are employed, it is preferred, in order to produce a commerciallyacceptable form of unit, and is one of the primary teachings of the present invention. to utilize either one pair of ports in excess of the number of cylinders employed, or to use one cylinder in excess of the pair of ports which are employed. As a consequence of this feature, the cylinder `block will be in proper sealing contact with the portedmember, but the relative speeds of these members will not 'be suiilciently high to result in difficulties being encountered. Additionally, the differential systemA should interposed planet gears. Other arrangements of a differential system are, however, possible, and,

in fact, under certain conditions differential systems might be devised which might not rely upon mechanical gears. Moreover, while one convenient form of control has been illustrated and described, it is apparent that this control, and especially the linkage forming a part thereof, might be modified or drastically revised.

With reference to the alternative form of differential mechanism illustrated in'Fig. 16, it will be noted that the reference numerals 49 and 6| identify the shafts heretofore identifiedwby these numbers and despite the fact that a slightly different arrangement of these parts is present. Sufce it to say that these shafts are connected to the upper and lower hydraulic units heretofore described, or to functional equivalents thereof.

' The gear H0 secured to shaft 49 is the gear which corresponds to gear |00 in the preceding views. In line with the end of shaft 49 a second shaft |4| is provided, and this shaft is connected through gears |42 and |43 to rotate the shaft 6|. Rotatably mounted upon the shafts |4| and 49 and adjacent the inner ends thereof is a casing |44 which provides within its body two chambers which are eccentric to the axes I4| and 49. These chambers each accommodate rotors |45 mounting `sliding vanes |46, and communication between the intervening wall |41 of these chambers is afforded by ports |48. Formed in the periphery of the casing |44 or otherwise suitably associated therewith are an annular series of gear teeth |49 which correspond in function to the gear or series of teeth 41 as heretofore described.

With this form of construction it is apparent thatwith al driving force acting to rotate the casing |44 and with the gear |40 held substantially stationary incident to the resistance to its movement, such turning of the casing will cause a'pumping action within its right hand compartment as viewed in Fig. 16. "In view ofthe fact that a completely trapped system is present, the uid under pressure cannot flow except through the proper port |41 and contact the blades of the left hand rotor as viewed in Fig. 16. Accordingly, the latter must act as a motor, driving the shaft |4|, and thru rotating the shaft 6|. When the action heretofore traced in connection with the upper and lower units takes place, and the shaft 6| assumes asubstantially `stationary condition, it is apparent that shaft( |4| will be likewise affected, and thus the left hand unit within the casing |44 will begin to act as a pump, driving the rotor within the right hand casing and accelerating the movement of shaft 49. When of course, the shaft 6| actually begins to act as a driving shaft, the condition Just described will be aggravated to an extent such that the speed of rotation of the right hand rotor within the casing |44 will be accelerated to a marked degree.

`With a view to harmonizing this structure to the structure heretofore described. the volume of the units is preferably such that the left hand unit bears a ratio of 3 to 1 with respect to the right hand unltwithin casing |44. Accordingly, with the initial condition of the parts, i. e., the

shaft 49 stationary and the casing |44 turning,

the shaft |4| will be turned at a speed approximately one third as great as the casing is turning. Conversely, with vthe shaft 6| substantially stationary, the right hand unit within casing |44 and, the shaft 49 Will l?? militia@ Fl? a Speed 69u81 to the speed of rotation of casing |44 plus a three time overdrive.

If `a planetary transmission is employed, it is to be understood that the driving member should preferably be the planet mountingunit. In this 1 mannera more eiiicient form of drive results, and

the drive is less likely to embody 'objectionable noise factors.

. To those skilled in art it will readily be apparfrom the spirit of the invention as defined bythe claims. a

Having thus described the invention,- what is claimed is:

1. A transmission including, `in combination, driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatable elements, one of said4 elements being connected to rotate with said driving shaft, a second of said elements being connectedv to rotate.'with said driven shaft, a fluid pump and motor, both said pump and motor being of the type which, when. inoperative, will provide barriers to a flow of liquid and each including a plurality of cylinders, valve mechanisms forming a part of said any given installation and without departing pump 'and motor, said valve mechanisms each providing for a vernier action of said valve mechanisms with respect to said cylinders, means providing fluid passages extending between the exhaust ports of the pump valve mechanism and the intake ports of the motor valve mechanism as well as between the exhaust ports-of the latter mechanism and the intake ports of the pump valve mechanism, said passages providing paths through which fluid may freely ow without reduction of pressure, pistons reciprocable within said pump and motor cylinders, means for connecting the pistons within said motor cylinders to said driven shaft, and a third element forming a part of said gearing and driven by and intermeshing with the rst named elements which form a part of said gearing,`said third element being connected to the pistonswithin saidpump cylinders for eecting reciprocation of -said latsa cylinder of the latter ywhile the piston therein i5 performing a working stroke.

2. Aftransmission including, in combination, driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatable elements, one of said elements being connected to rotate withsaid driving shaft, a second of said elements being connected to rotate with said driven shaft, a fluid pump and motor, both said pump and motor being of the type'which,

when inoperative, will provide barriers to a iiow m of 'liquid and each including a plurality of cylinders, valve mechanisms forming a part of said pump and motor, saidvalve mechanisms each presenting a plurality of pairs of ports different in number from the number of cylinders forming u parts of said pump and motor,-the outlet port of one pair being disposed adjacent the inlet port of the next succeeding pair, each of said pairs of ports including an intake port and an exhaust port. said valve mechanisms being movable with go respect to the cylinders of said pump and motor, means for effecting such relative movement and providing for a vernier action of said valve mechanisms with respect to said cylinders, means pro- .viding fluid passages extending between the ex- I haust ports of the pump vaive lmechanism and the intake ports of themotor valve mechanism as well as between the exhaust ports of the latter mechanism and the intake ports of the pump valve mechanism, said passages providing paths through which iiuid may freely flow without reduction of pressure, pistons reclprocable within y said pump and motor cylinders, means for connecting the pistons within said motor cylinders to said driven shaft, a third element forming a I part of said gearing and driven by and'intermeshing with the iirst named elements which form a part of said gearing, said third element being connected to the pistons within said pump cylinders for eifecting reciprocation of said lat- 40 ter pistons, the movements of the ports of the valve mechanisms with respect to the .cylinders being so timed that a piston within'avpump cylinder wilibe performing a discharge stroke while the outlet port of the pump valve mechanism 4l affords communication through the passage to an inlet portof the motor valve mechanism and to a cylinder of the latter while the piston therein 'is performing a working stroke, and means for varying thelength of travel of the pump pistons l to correspondingly vary and interrupt the displacement of fluid by said pump.

3. A transmission including, in combination,

driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatll able elements, one of said elements being connected to rotate with said driving shafts,` a second of said elements being connectedto rotatewith said driven shaft, a fluid pump and motor, both said pump and motor being `of the type U which, when inoperative, will provide barriers to a now of liquid and each including a plurality of cylinders, valvemechanismsforming a part of said pump and motor, said valve mechanisms each presenting a plurality of pairs of ports difd6 ferent in number from the number of cylinders forming parts of said pump and motor, the outlet port of one pair being disposed adjacent the inlet port of the'next succeeding pair each of said pairs of ports including. an intake port and an 'I0 exhaust port, saidrvalve mechanisms being`movable with respectto the cylinders of said pump and motor, means for effecting such relative movement and providing for a Vernier action of said valve mechanisms with respect to said cyl- 75 inders, means providing iiuid passages extending arvaass between the exhaust ports of the pump valve mechanism and the intake ports of the motor valve mechanism as well as between the exhaust ports of the latter mechanism and the intake ports of the pump valve mechanism, said pas- 5 sages providing paths through which Huid may freely iiow without reduction of pressure pistons reciprocable within said pump and motor cylinders, means for connecting the pistons within said motor cylinders to said driven shaft, a third 10 element forming a part of said gearing and driven by and intermhing with the first named elements which form a part of .said gearing, said third element being connected. to the pistons within said pump cylinders for eecting reciprocation of said latter pistons, the movements of the ports of the valve mechanisms with respect to the cylinders being so timedV that a piston within a pump cylinder will be performing a discharge stroke while the outn let port of the pump valve mechanism affords communication through the passage to an inlet port of the motor valve mechanism and to a cylinder of the latter while the piston therein is performing a working stroke and means for varying g5 the length of travel of the motor pistons and within the cylinders of said motor whereby to vary and interrupt the flow of fluid from said pump to said motor. l

4. A transmission including, in combination, driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatable elements, one of said elements being connected to rotate with said driving shaft, a second of said elements being 'connected to rotate 3 5' with said driven shaft, 'a fluid pump and motor, both said pump and motor being of the type which, when inoperative, will provide barriers to a iiow of liquid and each includinga plurality of cylinders, valve mechanisms forming a part of 40 said pump and motor, said valve mechanisms each presenting a plurality of pairs of ports different in number from the number of cylinders forming parts of said pump and motor, the inlet port of one pair being disposed adjacent the inlet .port of the next succeeding pair each of said pairs of ports including an intake port and an exhaust port, said valve mechanisms being movable with respect to the cylinders of said pump and motor, means'for eifecting'such relaso tive movement and providing for a vernier action of said valve 4mechanisms with respect to said cylinders, means providing uid passages extending between the exhaust ports of. the pump valve mechanism and the intake` ports of the Il motor valve mechanism as well as between the exhaust ports of the latter mechanism and the intake ports of the pump valve mechanism, said passages providing paths through which fluid may freely flow without reduction of pressure, O0 pistons reciprocable within said pump and motor cylinders, means for connecting the pistons within said motor cylinders to said driven shaft, a third element forming a part of said gearing and driven by and intermeshing with the mst named elements which form a part of said gearing, said third element being connected tothe pistons within said pump cylinders for effecting reciprocation of said latter pistons, the movements of the ports of the valve mechanisms with respect .70

to the cylinders Abeing so timed that a pistoul within a pump cylinder will be performing a discharge stroke while the outlet port of the pump valve mechanism affords communication through the passage to an inlet port of the motor valve the piston therein is performing a working stroke and means for varying the distance travelled by the pistons within both said pump and motor cylinders whereby to vary in inverse proportion the duid displaced by said pump and receivable in said motor and to interrupt such fluid flow.

5. A transmission including, in combination, driving and driven shafts, a gearing comprising aplurality of inter-meshing and relatively rotatable elements, one oi said elements being con-v nected to rotate with said driving shaft, a second of said elements being connected to rotate with said driven shaft, a uid pump and. motor, both said pump and motor being of the type which, when inoperative, will provide barriers to a flow or" liquid and each including a plurality of cylinders, valve mechanisms forming a part oi said pump and motor, said valve mechanisms each presenting a plurality of pairs of ports different in number from the number of cylinders forming parts oi said pump and motor, the outlet port ci one pair being disposed adjacent the inlet port (ifi of the next succeeding pair each of said pairs of ports including an intake port and an exhaust port, said valve mechanisms being movable with .respect to the cylinders of said pump and motor,

means for eecting such relative movement and providing for a Vernier action of said valve mechanisms with respect to said cylinders, means providing iiuid passages extending between the exhaust ports of the pump valve mechanism and the intake ports of the motor valve mechanism as well as between the exhaust ports of the latterV mechanism and the intake ports oi thev pump valve mechanism, said passages providing paths through which duid may freely ow without reduction oi pressure, pistons reciprocable within said pump and motor cylinders, means for connecting the pistons within said :motor cylinders to said driven shaft, a third-element forming a part of said gearing and driven by and intermeshing with the first named elements which form a part of said gearing, said' third element being connected to the pistons within said` pump cylinders lfor. enacting reciprccationpigsaidlatter pistons, the movements" oi 'the 'ports of the 'valve mechanisms with respect to the cylinders being so timed that a piston within a pump cylinder will be performing a discharge stroke whilev the outlet port of the pump valve mechanism affords communication through the passage to an inlet port of the motor valve mechanism and to a cylinder of the latter whileithe piston therein is performingl a `wormng stroke and means whereby said pump may be rendered inoperative to drive said motor, said third gearing element thereby providing a reaction point contributing to the driving oi said second named element by said rst named element. l

6. A transmission including, in combination, driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatable elements, one of said elements being connected to rotate with said driving shaft, a Second of said elements being connected to rotate with said driven shaft, a fluid pump and motor, both said pump and motor being of the type which, whenv inoperative, will provide barriers to a flow of liquid and each including a plurality lo! cylinders, valve mechanisms forming a part of said pump and motor, said valve mechanisms each presenting. a plurality of pairs of ports diil ferent in number from the number of cylinders forming parts oi saidpump and motorftheoutlet port of one pair being disposed adjacent the inlet port of the next succeeding pair each oi said pairs of ports including an intake port and an exhaust port, said valve mechanisms being movable with respect to the cylinders of said pump and motoxg means for eecting such relative f movement and providing for a vernier action of said valve mechanisms with respect to said cylinders, means providing :duid passages extending vbetween the exhaust ports of the pump valve mechanism and the intake ports oi the motor valve mechanism as Well as between the exhaust ports of the latter mechanism and the intake ports oi the pump valve mechanism, said passages providing paths through which fluid may freely flow without reduction oi v pressure, pistons reciprocable within said pump and motor cylinders, means for connecting the pistons within said motor cylinders to said driven shaft, a third Aelement forming a part of said gearing and driven by and intermeshing with the rst named elements which form a part of said gearing, said third element being connected to the pistons Within said pump cylinders for effecting reciprocation of said latter pistons, the movements of the ports of the valve mechanisms with respect to the cylinders being so timed that a piston within a pump cylinder will be performing a discharge ,Y stroke while the outlet port of the pump valve pressures developed within said passages for con- A trolling said last named means il A transmission including, in combination, driving and driven shafts, a gearing comprising a plurality of inter-meshing and relatively rotatable elements, one of said elements being connected to rotate with said driving shaft, a second of said elements being connected to rotate with said driven shaft, a uid pump and motor, both said pump` and motor being of the type' winch, l rvlienfinoperative, will provide barriersto a dow Hoi"ii'piid *and *eaci'iV including `a plurality of cylladers, valve mechanisnisforming apart ci said pump and motor, said valve mechanisms each presenting a plurality oi pairs oi ports different in number from the number oi cylinders forming parts oi said pump and motor, the outlet port of one pair being disposed adjacent the inlet port of the next succcedingpair each of said pairs of ports including an intake port and an exhaust port, said valve mechanisms being movable with respect to the cylinders of said pump and motor, means or effecting such relative movement and providirig'V for a Vernier action of said valve mechanisms with respect'to said cylinders, means proriding iiuid passages extending between the exhaast ports of the pump valve mechanism and the intake ports of the motor valve mechanism as iveli as between the exhaust ports of the latter mechanism and the intake yportici the pump valve mechanism, said passages providing paths through which :duid may freely ilow withform a part .of said gearingh said third element being. connected to the pistons within said pump 

